{"title":"Friction test machines for rubbery materials","authors":"A. Alliston-Greiner","doi":"10.1002/TT.3020010105","DOIUrl":"https://doi.org/10.1002/TT.3020010105","url":null,"abstract":"","PeriodicalId":23300,"journal":{"name":"Tribotest","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77823928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Factors affecting the mechanical stability of polyalkylmethacrylate type additives are comparatively examined for different shear degradation test methods and routine engine service, taking into account rheological and size exclusion chromatography data. The shear test methods are assessed regarding the MWD of the degraded additives. The extent of degradation of macromolecular additives and the molecular weight distribution (MWD) of the degraded products depend on the nature and extent of shear stress, average molecular weight, MWD, chemical structure, nature of the base oil and temperature. The shape of the MWD of the sonicated and automotive service subject additives was found to be similar, unlike that of the additives sheared by the diesel injector method. These are narrower and more dependent on the initial MWD of the additive, especially in the case of the additives with broader MWD. A shear test that better correlates with service has to take into account not only the control of shear stress, by appropriate calibration, but also a suitable degradation mechanism.
{"title":"Studies on the shear stability of macromolecular additives by size exclusion chromatography","authors":"M. Florea, P. Luca, S. Balliu","doi":"10.1002/TT.3020010104","DOIUrl":"https://doi.org/10.1002/TT.3020010104","url":null,"abstract":"Factors affecting the mechanical stability of polyalkylmethacrylate type additives are comparatively examined for different shear degradation test methods and routine engine service, taking into account rheological and size exclusion chromatography data. The shear test methods are assessed regarding the MWD of the degraded additives. \u0000 \u0000 \u0000 \u0000The extent of degradation of macromolecular additives and the molecular weight distribution (MWD) of the degraded products depend on the nature and extent of shear stress, average molecular weight, MWD, chemical structure, nature of the base oil and temperature. The shape of the MWD of the sonicated and automotive service subject additives was found to be similar, unlike that of the additives sheared by the diesel injector method. These are narrower and more dependent on the initial MWD of the additive, especially in the case of the additives with broader MWD. A shear test that better correlates with service has to take into account not only the control of shear stress, by appropriate calibration, but also a suitable degradation mechanism.","PeriodicalId":23300,"journal":{"name":"Tribotest","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76987638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper reports on the method and preliminary results of a significant modification of the Noack volatility test. This modification permits collection and examination of the volatile products as well as of the residue. The analysis of such volatiles by chromatography and spectroscopy revealed surprising information that is especially relevant in the face of increasingly difficult automotive and heavy duty engine emission limitations. The data also showed very close agreement with the Unified Test Method for the Noack Volatility Test now covered by CEC L-40-T-87. Important to operators, the authors' modified Noack apparatus avoids the use of the toxic Wood's Metal of the earlier Noack apparatus.
{"title":"A new approach to the Noack volatility test","authors":"T. Selby, E. Reichenbach, R. H. Hall","doi":"10.1002/TT.3020010102","DOIUrl":"https://doi.org/10.1002/TT.3020010102","url":null,"abstract":"This paper reports on the method and preliminary results of a significant modification of the Noack volatility test. This modification permits collection and examination of the volatile products as well as of the residue. The analysis of such volatiles by chromatography and spectroscopy revealed surprising information that is especially relevant in the face of increasingly difficult automotive and heavy duty engine emission limitations. The data also showed very close agreement with the Unified Test Method for the Noack Volatility Test now covered by CEC L-40-T-87. Important to operators, the authors' modified Noack apparatus avoids the use of the toxic Wood's Metal of the earlier Noack apparatus.","PeriodicalId":23300,"journal":{"name":"Tribotest","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86865833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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